load west0479
s = svd(full(west0479));
sl = svds(west0479,4);
ss = svds(west0479,6,0);
subplot(2,1,1)
plot(s(1:4),'ks'), hold on
plot(sl,'k+'), hold off
title('4 largest singular values of west0479')
legend('svd(A)','svds(A,4)')
set(gca,'XLim',[0.5 4.5])

subplot(2,1,2)
plot(s(end-5:end),'ks'), hold on
plot(ss,'k+'), hold off
title('6 smallest singular values of west0479')
legend('svd(A)','svds(A,6,0)')
set(gca,'XLim',[0.5 6.5])

svds(west0479,1)
max(svd(full(west0479)))
norm(full(west0479))

normest(west0479)

n = 3;
for i=1:n
    for j=1:n
      A(i,j) = sym(1/(i-j+1/2));
   end
end
[U,S,V] = svd(A)